Thesis
Consequences of pre-emergent herbicides on production and symbiosis of Ornithopus sativus Brot. cv. Fran2O
Honours, Murdoch University
2023
Abstract
The effects of three herbicides applied to Ornithopus sativus Brot. subsp. sativus cv. Fran2o was studied on an acidic sandy loam in Northam, Western Australia. The herbicides were applied as both post-sown pre-emergent and incorporated by sowing methods of application. Diuron and simazine (group 5 herbicides), inhibitors of photosystem II, significantly reduced nodulation, nitrogen-fixing capability and peak biomass of O. sativus cv. Fran2o. Imazethapyr (group 2 herbicide), an inhibitor of the acetolactate synthase, did not reduce nodulation or biomass but did decrease the capacity of O. sativus cv. Fran2o to fix nitrogen by approximately 40%. Dose-response modelling of shade house grown O. sativus cv. Fran2o plants indicated all herbicides reduced nodulation at lower application rates, yet plant biomass was affected at higher application rates. These results suggest plant-rhizobia symbiosis in O. sativus cv. Fran2o is more sensitive to herbicide damage than the plant itself. This is a factor that producers must consider when implementing their herbicide regimes to maximise nitrogen fixation. The extent of herbicide toxicity to response variables of O. sativus cv. Fran2o was found to vary greatly between modes of action. When incorporating the tested herbicides in a pre-emergent fashion, incorporate by sowing was found to be less harmful to O. sativus cv. Fran2o than post-sown pre-emergent applications.
Details
- Title
- Consequences of pre-emergent herbicides on production and symbiosis of Ornithopus sativus Brot. cv. Fran2O
- Authors/Creators
- Benedict Arthur
- Contributors
- Graham O'Hara (General Contributor) - Murdoch University, Centre for Sustainable Farming SystemsRonald J Yates (General Contributor)
- Awarding Institution
- Murdoch University; Honours
- Identifiers
- 991005599168507891
- Murdoch Affiliation
- School of Agricultural Sciences
- Resource Type
- Thesis
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